In order for the item to be sold to you, you had to click twice that you were accepting the sale.
Ask those who have access to your computer who has been playing around. That person owes you the money to pay for the goods.
You can pay for the item.
or
You can refuse to pay for the item. You will get an Unpaid Item Strike which will make it difficult to bid or buy on eBay in future.
If you already have Strikes, and have not learned from them that eBay frowns on deadbeats, you will be removed from the site.